For this thing is very close to you, in your mouth and in your heart, so you can fulfill it.
The “thing” referred to in this verse is the Torah in general (Rashi) and the directive to return to G-d in particular (Ramban). G-d assures us that we always possess the inner capability to lead full, consummate lives, no matter how far we are, physically or spiritually, from where we should be. It is only a matter of exercising our free choice to do so.
When inspired by an inner drive to return to G-d and cling to Him, studying the Torah and observing G-d’s commandments become natural and accessible.
Returning to G-d, after all, is returning to our authentic, innermost selves. When we allow our inner essence to shine, the interference from conflicting drives and façades that we so often convince ourselves that we must maintain disappears. Our direction becomes clear, and we become surprised by the power we suddenly possess to improve our behavior, to inspire others, and to affect the world.
--Daily Wisdom Volume 3